[Gllug] Re: Memory usage

[Peter Grandi]

>>> On Thu, 13 Oct 2005 14:33:16 +0100, Tethys <sta296 at astradyne.co.uk>
>>> said:

sta296> Peter Grandi writes:

>> It is hard to believe that your OOo when starting from cache
>> takes a large fraction of 13 seconds of CPU time on a CPU
>> probably twice as fast as mine. So perhaps it is either a
>> debug-flags build, or it is still groping for way too many
>> files, but then they should be cached...

sta296> With a hot cache:

sta296> 	leto:~% time oowriter
sta296> 	javaldx: Could not find a Java Runtime Environment! 

sta296> 	real    0m11.926s
sta296> 	user    0m9.220s
sta296> 	sys     0m3.109s

Well, here there is something REALLY WRONG (perhaps I should use
'banner' here to write it in large, not just capital, letters
:->).

Firstly the elapsed time is SMALLER than the sum of user and
system CPU time, which may mean that your disks are faster than
light and read blocks _before_ the program requests them :-).

More seriously, this may happen if you got two CPUs and they are
both hit very heavily, for whatever reason, and of course there
being a hot cache the disk is not causing a lot of wait.

On a 3GHz CPU, a user CPU time of 9 seconds is extremely
worrying, and the 3 seconds of system CPU time are simply
insane...

Consider the comparison with my 1.6GHz single CPU hot cache
start for the emtpy page Writer (about 1-2 second longer than
for empty window Office):

  $  time soffice -writer

  real    0m4.747s
  user    0m3.120s
  sys     0m0.320s

In particular note that my system time is one tenth yours, even
if I run on a CPU that is twice as slow.

So, either there are evil gremlins in your system, or something
funny is happening.

I'll repeat:

* Investigate, especially if your CPU is HT, whether you have an
  older kernel with a scheduler that does not support sticky
  affinity; try to boot a non SMP kernel.

* Use a production build of OOo 1.1.5, freshly installed. If you
  have a debug build it may be slower, however not in the
  appalling measure above.

sta296> Personally, I consider that to be a bug. Abiword and
sta296> gnumeric manage just fine, and start up in a couple of
sta296> seconds at most.

Uhm, but they are not frameworks/suites. Also, the CPU times
above indicate something is wrong with your system indeed.

Having the home dir on NFS surely does not help with processes
that do a lot of accesses to many files, especially BTW if
little ones. But starting an empty-age Writer does few accesses
to the home dir, almost all are accesses to OOo's own files and
bits in the system dirs, and I hope you don't have those on NFS.


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